Corrosion inhibitors

ABSTRACT

The reaction of an α,β-ethylenically unsaturated aldehyde with organic amines which is further reacted with a carboxylic acid, organic halide or an epoxide-containing compound are employed as corrosion inhibitors for preventing corrosion of ferrous metals in contact with corrosive brine, oil and gas well fluids.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.782,653 filed Oct. 1, 1985 (now abandoned) which is acontinuation-in-part of application Ser. No. 594,518 filed Mar. 29, 1984(now abandoned).

BACKGROUND OF THE INVENTION

The present invention relates to new and useful corrosion inhibitors andin particular to corrosion inhibitors which materially reduce theeffects of attack of reactive materials on metals of construction.

In oil producing applications, metal tubing, sucker rods, valves,screens, coatings, pumps, and the like are subjected to the action ofextremely corrosive fluids and gases. Such sweet and/or sour corrosivecompositions can contain dissolved materials such as hydrogen sulfide,sulfur dioxide, carbon dioxide, oxygen, mineral acids, organic acids,and the like, as well as mixtures thereof.

Numerous processes for inhibiting the corrosion of metals caused uponexposure to corrosive oil and gas well fluids have been proposed. See,for example, U.S. Pat. Nos. 2,643,977 and 3,077,454. Unfortunately, suchprocesses are not effective under the conditions of high temperaturesand pressures experienced by metal equipment in extremely deep oil andgas wells. Such conventional corrosion inhibitors can have a tendency todegrade, volatilize, or polymerize causing formation damage and/orinadequate corrosion protection.

In view of the deficiencies of the prior art, it would be highlydesirable to provide a corrosion inhibitor which is easily prepared andcan be effectively employed under very high temperature and pressureconditions.

SUMMARY OF THE INVENTION

The present invention pertains to a new composition of matter whichcomprises the product resulting from reacting at a temperature of fromabout 25° C. to about 250° C. for a time sufficient to render thereaction complete as determined by halide or residual acid numbertitrations

(I) the product resulting from reacting, in the presence or absence of asuitable solvent,

(A) at least one aliphatic α,β-monoethylenically unsaturated aldehydehaving from about 3 to about 6 carbon atoms; and

(B) at least one organic diamine represented by the formula ##STR1##wherein R is a divalent saturated C₂ to C₄ aliphatic hydrocarbon group;each R¹ and R² is independently hydrogen or a saturated alkyl amino oran alkyloxy group containing from 2 to about 4 carbon atoms or when twoadjacent R2 groups are taken together, they form a bridging alkyleneradical containing 2 carbon atoms such that the R group containing 2carbon atoms and two adjacent R² groups and two nitrogen atoms form aheterocyclic ring containing 4 carbon atoms and 2 nitrogen atoms: x hasa value from 1 to about 8 and

wherein components (A) and (B) are employed in a mole ratio of (A) to(B) of from about 1:1 to about 1:6: and

(II)

(A) at least one saturated or unsaturated, cyclic or acyclic aliphaticmono- or polycarboxylic acid having from about 2 to about 50 carbonatoms; or

(B) at least one saturated or unsaturated, cyclic or acyclic aliphaticalkyl monohalide or alkyl polyhalide having from about 2 to about 50carbon atoms; or

(C) a combination of (A) and (B);

wherein components (I) and (II) are employed in quantities which providefrom about 0.4 to about 1, suitably from about 0.55 to about 0.85, moresuitably from about 0.65 to about 0.75 equivalent of carboxyl and/orhalide groups from component (II) for each theoretically active aminohydrogen atom contained in component (I).

The present invention provides corrosion protection to metalcompositions exposed to corrosive fluids (gases and/or liquids) at hightemperatures and pressures, such as are experienced in deep oil and gaswells, geothermal wells, brines and the like.

In another aspect, the present invention is a process for preventing thecorrosion of a metal composition in contact with corrosive fluids, whichprocess comprises contacting the surface of said metal composition withan effective amount of the aforementioned corrosion inhibitor.

DETAILED DESCRIPTION OF THE INVENTION

The corrosion inhibitors of the present invention can be prepared byconveniently conducting the reaction, quaternization or neutralizationat temperatures from about 0° C. to about 300° C. The neutralization ispreferably carried out at temperatures of from about 0° C. to about 100°C. while the reaction is preferably carried out at temperatures of fromabout 150° C. to about 250° C. and the quaternization reaction ispreferably carried out at a temperature of from about 25° C. to about250° C.

The α,β-ethylenically unsaturated aldehydes useful herein can begenerally represented by the formula: ##STR2## wherein each R, R¹ and R²are individually hydrogen, alkyl, aryl, aralkyl or substituted alkyl,aryl or aralkyl. Substituents include, for example, halo, alkoxy andamino groups. Examples of suitable α,β-monoethylenically unsaturatedaldehydes are disclosed in U.S. Pat. No. 3,459,710 which is incorporatedherein by reference. Other such aldehydes include, for example,furfural, methyl acrolein, bromo- or chloro-cinnamaldehyde, and hexenal.The preferred α,β-monoethylenically unsaturated aldehyde is acrolein ormixtures thereof with other aldehydes.

The organic polyamines of this invention can include those organicdiamines of the type disclosed in the aforementioned U.S. Pat. No.3,459,710. See also those polyamines disclosed in U.S. Pat. No.4,292,413. Other polyamines include, for example, triethylenetetraamine,tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine,polyoxypropyleneamine, iminobispropylamine,2-(2-aminoethylamino)ethanol, N-decyl-1,2-ethanediamine,N-undecyl-1,2-ethanediamine, N-tridecyl-1,2-ethanediamine,N-pentadecyl-1,2-ethanediamine, N-hexadecyl-1,2-ethanediamine,N-heptadecyl-1,2-ethanediamine, N-octadecyl-1,2-ethanediamine,N-decyl1,3-propanediamine, N-dodecyl-1,2-propanediamine,N-tetradecyl-1,3-propanediamine, N-hexadecyl-1,3-propanediamine,N-heptadecyl-1,3-propanediamine, N-octadecyl-1,2-propanediamine,N-octadecyl-1,3-propanediamine, octadecen-1,3-propanediamine, and thelike as well as mixtures thereof. In addition, ammonia andmonofunctional amines can be utilized. Monofunctional amines include1-decanamine, 1-undecanamine, 1-dodecanamine, 1-tridecanamine,1-tetradecanamine, 1-pentadecanamine, 1-hexadecanamine,1-heptadecanamine, 1-octadecanamine, 9-octadecen-1-amine,9,12-octadecadien-1-amine, 9,12,15-octadecatrien-1-amine,9-eicosen-1-amine, tallow amine, cocoamine, diglycolamine, and the like.Of the foregoing polyamines, those polyamines containing at least oneprimary amine are preferred; with those polyamines capable of formingimidazolidine or hexahydropyrimidine moieties or substituted moietiesthereof being most preferred. Polyamines can be ethoxylated,propoxylated, butoxylated or polyethoxylated, polypropoxylated orpolybutoxylated. Preferred polyamines are ethylenediamine andpropylenediamine.

Particularly suitable organic amines which can be employed in thepresent invention include those represented by the formulas ##STR3##wherein each R¹ and R² is independently hydrogen or a hydrocarbyl groupor hydroxyl substituted hydrocarbyl group or amine substitutedhydrocarbyl group having from 1 to about 36, preferably from about 1 toabout 3 carbon atoms, each R³ is independently a divalent hydrocarbylgroup having from 1 to about 36, preferably from 1 to about 3 carbonatoms; m has a value from zero to about 8, m' has a value from 1 toabout 4, n has a value of 2 or 3 and n' has a value from about 1 toabout 10. The term hydrocarbyl as employed herein means any aliphatic,cycloaliphatic, aromatic, aryl substituted aliphatic groups or aliphaticsubstituted aromatic groups.

The compounds comprising a functionality and/or functionalities (i.e.substituted groups) capable of undergoing a reaction, quaternization orneutralization with an amine include, for example, compounds comprisingcarboxylic acid moieties, organic halide moieties, epoxide moieties, andthe like. For example, a carboxylic acid moiety can react with an amineto form a salt, amide or amidine-type linkage. Most preferably,substituent compounds include the polycarboxylic acids, organicpolyhalides and polyepoxides. Such compounds are capable of introducingdesired crosslinking to the product. Monocarboxylic acid compounds,organic monohalides and monoepoxide compounds can be employed. Examplesof suitable carboxylic acids include acetic acid, benzoic acid, phthalicacid, terephthalic acid, myristic acid, palmitic acid, oleic acid,isostearic acid, capric acid, caprylic acid, lauric acid, tall oil fattyacids, 5-carboxy-4-hexyl-2-cyclohexene-1-octanoic acid,6-carboxy-4-hexyl-2-cyclohexene-1-octanoic acid, dimer acids, trimeracids and similar mono- and polycarboxylic acids. Other suitable acidsare disclosed in U.S. Pat. No. 4,339,349, which is incorporated hereinby reference. Examples of suitable mono- and polyepoxides includedodecyloxirane, tetradecyloxirane, hexadecyloxirane,2-decyl-3-hexyloxirane, 2,3-dioctyloxirane, octadecyloxirane,2-decyl-3-(5-methylheptyl)oxirane, (dodecyloxy)methyl oxirane,(tetradecyloxy)methyl oxirane, epoxidized vegetable oils such asepoxidized linseed oil, epoxidized carboxylic acids such as epoxidizedoleic acid, the glycidyl ethers, and the like. See U.S. Pat. No.4,292,413 for representative epoxide compounds. Examples of suitableorganic halides include 1-chlorodecane, 1-bromodecane, 1-bromoundecane,1-bromododecane, 1-iodododecane, 1-chlorotetradecane,1-bromotetradecane, 1-bromopentadecane, 1-chlorohexadecane,1-bromohexadecane, 1-chlorooctadecane, 1-bromooctadecane,1-iodooctanedecane, 2-bromododecane, 2-bromotridecane,1,12-dibromododecane, 1,2-dibromohexadecane, 1,2-dibromooctadecane,benzyl chloride, benzyl bromide, p-dodecylbenzyl chloride, and the like.Other suitable organic halides are disclosed in U.S. Pat. No. 4,315,087,which is incorporated herein by reference. Other suitable compoundscomprising a functionality or functionalities capable of undergoing areaction, quaternization or neutralization with an amine include, forexample, inorganic acids, aldehydes, alkylene oxides, cyanides,nitriles, sulfur containing compounds such as mercaptans, and the like.Preferably, the substituent compound has a predominantly hydrophobiccharacter.

Suitable acetylenic alcohols which can be employed herein include, forexample, 2-propyn-1-ol (propargyl alcohol), 2-butyn-1-ol, 3-butyn-1-ol,3-butyn-2-ol, 2-methyl-3-butyn-1-ol, 2-methyl-3butyn-2-ol,1-pentyn-3-ol, 3-pentyn-1-ol, 4-pentyn-2-ol, 3-hexyn-1-ol, 5-hexyn-1-ol,3-ethyl-4-hexyn-3-ol, 5,5-dimethyl-2-hexyn-1-ol,3-(2-methylpropyl)-5-hexyn-2-ol, 2,3,4,4-tetramethyl-5-hexyn-3-ol,1-heptyn-3-ol, 5-heptyn-1-ol, 4-methyl-1-heptyn-4-ol,6-methyl-2-heptyn-4-ol, 4-propyl-1-heptyn-4-ol, 1-octyn-3-ol,1-octyn-4-ol, 2-octyn-1-ol, 4-octyn-3-ol, 7-octyn-1-ol,7-methyl-2-octyn-1-o1,2-methyl-4-octyn-2-ol, 3-ethyl-5-octyn-3-ol,4-ethyl-1-octyn-3-ol, 3,7-dimethyl-1-octyn-3-ol, 1-nonyn-3-ol,3-nonyn-1-ol, 7-nonyn-1-ol, 1-decyn-3-ol, 2-decyn-4-ol, 9-decyn-4-ol,mixtures thereof and the like.

Suitable aliphatic and aromatic aldehydes which can be employed hereininclude, for example, formaldehyde, acetaldehyde, propanal, butanal,pentanal, 2-methylbutanal, hexanal, octanal, nonanal, decanal,undecanal, 2-methylundecanal, dodecanal, tridecanal, tetradecanal,octadecanal, benzaldehyde, 2-bromobenzaldehyde, 2-methoxybenzaldehyde,2,3-dimethoxybenzaldehyde, benzeneacetaldehyde, 3-phenyl-2-propenal,2-methyl-3-phenyl-2-propenal, 2-chloro-3-phenyl-2-propenal,2-bromo-3-phenyl-2-propenal, 3,3-diphenyl-2-propenal,3-(2-nitrophenyl)-2-propenal, mixtures thereof and the like.

Products used in this invention are preferably prepared by firstreacting the organic polyamine with the α,β-ethylenically unsaturatedaldehyde. Preferably, the reaction is carried out in an inert atmosphereand at a temperature between about 0° C. and about 150° C. The choice ofinert solvent is generally dependent upon the boiling point of thepolyamine, the solubility of the polyamine and the solubility of theresulting polymer. Advantageously, the solvent is one in which both themonomers and resultant polymer are soluble. Suitable solvents includemethanol, ethanol, isopropanol, butanol, benzene, water, dioxane,dimethylformamide, tetrahydrofuran, and the like.

Preferably nearly equimolar amounts of polyamine and unsaturatedaldehyde are employed. Preferably, the organic polyamine is dissolved ina suitable solvent in a reaction vessel. A solution of the unsaturatedaldehyde and suitable solvent is then contacted with the polyaminesolution, preferably in a slow manner. The reaction mixture can becooled or heated. Solvent can be removed by distillation. Preferably, asolvent, such as isopropanol can be added to the reaction mixture inorder to create an azeotropic mixture for removing solvent andby-product.

Oligomer or polymer products obtained from the reaction ofα,β-ethylenically unsaturated aldehydes with organic polyamines, usuallyhave an average molecular weight less than about 1,000. The polymers oroligomers within the scope of this invention comprise compounds havingone or more vinyl, imine, enamine, ether, or hydroxyl functional groups.The reaction of an amine containing piperazine rings with anα,β-ethylenically unsaturated aldehyde introduces piperazine rings intothe constituents of the product. The reaction of the carbonyl ofα,β-monoethylenically unsaturated aldehyde with a primary amine forms animine which readily cyclizes if labile (where the term "labile" is asdefined in U.S. Pat. No. 4,315,087) amine hydrogens are available,preferably in the γ (gamma) or δ (delta) position relative to thenitrogen of the imine. An imidazolidine ring is formed from the reactionof the carbonyl of an α,β-monoethylenically unsaturated aldehyde with anethylenepolyamine while a hexahydropyrimidine ring is formed from thereaction of the carbonyl of an α,β-monoethylenically unsaturatedaldehyde with a propylenepolyamine. Some of the possible constituents ofthe oligomers formed from the reaction of, for example, acrolein withethylenediamine are believed to be represented by the followingstructures, although the authors do not wish to be limited by thistheory: ##STR4##

The product which is isolated can be contacted with the compoundcomprising a functionality or functionalities capable of undergoing areaction, quaternization or neutralization with an amine. The previouslydescribed product is dissolved or dispersed in a suitable solvent andcontacted with the substituent compound which is also dissolved in asuitable solvent. The amount of substituent compound which is employedcan vary such that about 1 to about 100 percent of the available aminohydrogens of the polyamine/unsaturated aldehyde product can be reactedwith reactive functionalites of the substituent compound. This resultingproduct can, if desired, be isolated using techniques such asdistillation to remove by-products and solvent.

The resulting product can be employed as a corrosion inhibitor as areconventional corrosion inhibitors. Generally, the product can beemployed in corrosion inhibitor formulations as are known in the art.For example, the product can be dispersed or dissolved in a suitablecarrier liquid or solvent such as water, alcohols, aromatic andaliphatic hydrocarbons, and the like, or mixtures thereof. Otheradditives include demulsifiers, water wetting agents, surfactants,viscosifiers, commingled gases, defoamers, other corrosion inhibitorssuch as polymeric materials and salts, organic and inorganic acids, ironcontrol agents, sequestering and/or chelating agents, phosphates,quaternaries, amine salts, and the like. For example, surface activeagents are used to assure complete dispersion of active ingredientsthroughout the corrosion inhibitor composition and thus provide a bettercontact of the corrosion inhibitor with the surface of the metalcompound which is being protected. The corrosion inhibitors of thisinvention form films on metal surfaces at least as readily as thoseknown film forming corrosion inhibitors.

The corrosion inhibitor of this invention is employed in a functionallyeffective amount. That is, any quantity of corrosion inhibitor whichwill provide some degree of inhibition of corrosion is sufficient.Typical amounts of corrosion inhibitor which are employed in an oiland/or gas well treatment can range from about 5 to about 2,000 ppm forcontinuous treatment or about 1,000 to about 50,000 ppm for squeezetreatment, based on the weight of corrosive well fluids in contact withthe metal compositions which are protected. Amounts of corrosioninhibitor in excess of 50,000 ppm can provide additional corrosioninhibition but at increased expense.

The corrosion inhibitors of this invention are highly stable to hightemperatures and high pressures. Typically, corrosion inhibitors areemployed in applications where temperatures range from about 20° F. toin excess of about 500° F., typically from about 100° F. to about 400°F., depending upon the composition of the polymer product. The corrosioninhibitors of this invention are especially useful at temperaturesranging from 300° F. to about 450° F.

The corrosion inhibitors of the present invention act to protect metalcompositions from corrosive effects of fluids (liquids and gases) whichare present in, for example, down hole well environments. Such corrosiveenvironments include, brines such as aqueous solutions of inorganicsalts such as, for example, alkali and alkaline earth and transitionmetal salts such as, for example, sodium chloride, calcium chloride,magnesium chloride, calcium bromide, zinc bromide, mixtures thereof andthe like. Other corrosive environments include, acids or acid gases suchas, for example, hydrogen sulfide, hydrochloric acid, acetic acid,formic and carbon dioxide in the presence of water, combinations thereofand the like. Metal compositions typically include steel, iron, ferrousalloys, and other alloys of which typical sucker rods, valves, pumps,tubing and the like are comprised.

The corrosion inhibitors of this invention inhibit corrosion to metalcompositions used in, for example, down hole applications, preferably inexcess of 80 percent corrosion protection. The corrosion inhibitorsadvantageously inhibit corrosion to metal compositions at elevatedtemperatures exceeding 250° C. in oil and gas well applications. Usefulapplications include oil and/or gas well drilling, completion, workover,stimulation, transfer, processing and storage applications.

The following examples are presented to further illustrate but not limitthe scope of this invention.

PREPARATION OF CORROSION INHIBITORS FOR EVALUATION IN DYNAMlC WHEEL TESTAT 175° F. (79.4° C.) AND 350° F. (177° C.) EXAMPLE 1

Acrolein was distilled in the presence of 358 ppm and 379 ppm ofhydroquinone in the boiling and receiving flasks, respectively. Asolution of distilled acrolein was prepared by mixing 282.1 grams (g)acrolein with about 155 g methanol.

Into a 2-liter reactor equipped with mechanical stirrer, immersionthermometer, condensor, addition funnel and nitrogen purge system wasplaced a solution of 300 g ethylenediamine and about 510 g methanol. Thereactor contents were stirred under nitrogen atmosphere while being heldat a temperature of about 4° C.

The acrolein solution was added to the reactor over a period of 160minutes (9600 s) at such a rate that the rise in temperature did notexceed 23° C. The mixture was subjected to rotary evaporation at 100° C.An amount of isopropanol was added to the mixture and said mixture wasagain subjected to rotary evaporation at 100° C. The product was ayellowish viscous liquid.

EXAMPLE 2

A reaction product of acrolein and ethylenediamine(ethylenediamine/acrolein oligomers) was prepared and isolated asdescribed in Example 1. About 141.6 g of this product was mixed withabout 47.5 g methanol to form a solution. The solution was charged intoa reactor of the type described in Example 1.

A solution containing 18.5 g of a C₁₂ -C₁₄ mixture was stirred andrefluxed at about 68.5° C. After addition was complete, the mixture wasstirred overnight at room temperature. The mixture was subjected torotary evaporation at 100° C. The product was a reddish-brown viscousliquid.

EXAMPLE 3

136.1 g of ethylenediamine/acrolein oligomers of Example 1 was disslvedin 785 g isopropanol.

A solution containing 249.3 g of Westvaco Diacid 1550 (a liquidmonocyclic C₂₁ dicarboxylic acid represented by the following formula:##STR5## which is commercially available from Westvaco Corporation) and136.1 g isopropanol was charged into a reactor of the type described inExample 1. To this mixture was added the previously described productmixture. The resulting mixture was refluxed at 86° C. for 30 minutes(1800 s), producing a product, which was believed to be a salt, inisopropanol.

EXAMPLE 4

The mixture from Example 3 was refluxed at 90° C. Water and isopropanolwere removed by using a Barrett trap. The reactor contents were heatedfor about 285 minutes (17,100 s) at about 170° C. to 230° C. Thisreaction product was cooled to room temperature, and a reddish-brownsolid resulted. The product (308.7 g) was redissolved in isopropanol(505 grams).

EXAMPLE 5

A solution containing 411 g tall oil fatty acid, 57 g of Westvaco Diacid1550 described in Example 3 and 87 g isopropanol was charged into araactor. To this mixture was added 109 g of the ethylenediamine/acroleinoligomers of Example 1 which was dissolved in 386 g isopropanol. Theresulting mixture was refluxed at 200° C. Water and isopropanol wereremoved using a Barrett trap. The reactor contents were heated for about370 minutes (22,200 s) between 165° C. to 200° C. The reddish-brownproduct was cooled to 80° C. and 310 g isopropanol was added. Thismixture was cooled to room temperature.

EXAMPLE 6

Into a reactor equipped with stirrer, thermometer, condenser andaddition funnel with nitrogen inlet tube was placed a solution of 490 gof Ethyleneamine E-100 and 460 g methanol. Ethyleneamine E-100 is amixture of tetraethylenepentamine, pentaethylenehexamine andhexaethyleneheptamine with an average molecular weight of about 300which is commercially available from The Dow Chemical Company. Thereactor contents were stirred under nitrogen atmosphere while being heldat a temperature of about 4° C.

A solution of acrolein was prepared by mixing 168 g of distilledacrolein with about 160 g methanol. The acrolein was added to thereactor over a period of 145 minutes (8700 s) at such a rate that therise in temperature did not exceed 18° C. The mixture was subjected torotary evaporation at 100° C. An amount of isopropanol was added to themixture and said mixture was again subjected to rotary evaporation at100° C. The product was a reddish-brown viscous liquid.

EXAMPLE 7

112 g of the Ethyleneamine E-100/acrolein oligomers of Example 6 waspoured into a reactor of the type described in Example 1. A solutioncontaining 436 g of the diacid described in Example 3 and 390 gisopropanol was added to the product. The resulting mixture was refluxedat 180° C. Water and isopropanol were removed by using a Barrett trap.The reactor contents were heated for about 120 minutes (7200 s) at about170° C. to 180° C. The reaction product was cooled to 80° C. and 315 gisopropanol added. On cooling to room temperature a reddish brown liquidresulted.

EXAMPLE 8

Ethylenediamine (120.2 grams, 2 moles) and methanol (157.22 grams) wereweighed into a 1-liter resin kettle equipped with an immersionthermometer, condenser, mechanical stirrer, addition funnel and nitrogenpurge system. The reactor contents were cooled to less than 10° C. Amethanolic solution of acrolein was prepared by mixing 56.06 gramsdistilled acrolein (1 mole) with 56.06 grams methanol. The methanolicsolution of acrolein was added dropwise to the methanolic solution ofethylenediamine at such a rate that the rise in temperature did notexceed 10° C. The reactor contents were subjected to rotary evaporationunder full vacuum at 93° C.

The ethylenediamine/acrolein oligomers (9.63 grams), Westvaco Diacid1550 (34.47 grams, 0.1 mole) and isopropanol (204 grams) were weighedinto a 1-liter resin kettle equipped with an immersion thermometer,mechanical stirrer, nitrogen purge system and condenser. The reactorcontents were refluxed at 82° C. for one hour (3600 s). Then isopropanoland water were removed by using a Barrett trap as the reactiontemperature was increased from 84° C. to 210° C. The reactor contentswere heated an additional 210 minutes (12,600 s) at 210° C., cooled toroom temperature and dissolved in isopropanol (78.79 grams) by refluxingat 84° C. for one hour (3600 s).

EXAMPLE 9

Ethylenediamine (120.2 grams, 2 moles) and isopropanol (77.9 grams) wereweighed into a 1-liter resin kettle of the type described in Example 8.The reactor contents were stirred while cooled to 10° C. An isopropanolsolution of acrolein was prepared by mixing 88.1 grams distilledacrolein (1.57 moles) with 38.8 grams isopropanol. The isopropanolsolution of acrolein was added dropwise to the isopropanol solution ofethylenediamine over a period of 73 minutes (4380 s) at such a rate thatthe rise in temperature did not exceed 30° C. Isopropanol (78.4 grams)was added to the reactor contents and the reactor contents stirred for15 hours (54,000 s) at room temperature. The reactor contents wererotary evaporated under full vacuum at boiling water temperature.

The resultant ethylenediamine/acrolein oligomers (66.66 grams), WestvacoDiacid 1550 (146.59 grams, 0.42 mole) and isopropanol (635.69 grams)were weighed into a 2-liter resin kettle equipped with an immersionthermometer, mechanical stirrer, condenser and nitrogen purge system.The reactor contents were refluxed between 80°-82° C. for one hour (3600s). Isopropanol and water were removed with a Barrett trap as thereaction temperature was increased from 82° C. to 210° C. The reactorcontents were heated an additional 210 minutes (12,600 s) at 210° C.,cooled to room temperature and dissolved in isopropanol (304.55 grams)by refluxing at 82° C. for 60 minutes (3600 s).

EXAMPLE 10

N-(2-Aminoethyl)piperazine (253.3 grams, 1.96 moles) and methanol (8118grams) were weighed into a 1-liter resin kettle of the type described inExample 8. The reactor contents were stirred while cooled to 10° C. Amethanolic solution of acrolein was prepared by mixing 44.85 gramsdistilled acrolein (0.8 mole) with 24 grams methanol. The methanolicsolution of acrolein was added dropwise to the methanolic solution ofN-(2-aminoethyl)piperazine over a period of 175 minutes (10,500 s) atsuch a rate that the rise in temperature did not exceed 25° C. Thereactor contents were rotary evaporated under full vacuum at boilingwater temperature. Isopropanol was added to the rotary evaporationbottoms and this mixture was again subjected to rotary evaporation underfull vacuum at boiling water temperature.

The resultant N-(2-aminoethyl)piperazine/acrolein oligomers (129.88grams), Westvaco Diacid 1550 (241.08 grams, 0.68 mole) and isopropanol(798.54 grams) were weighed into a 2-liter resin kettle of the typedescribed in Example 9. The reactor contents were refluxed at 82° C. for60 minutes (3600 s). Then isopropanol and water were removed with aBarrett trap as the reaction temperature was increased from 82° C. to210° C. The reactor contents were heated an additional 210 minutes(12,600 s) at 210° C., cooled to room temperature and dissolved inisopropanol (565.12 grams) by refluxing between 80° C. to 82° C. for onehour (3600 s).

EXAMPLE 11

Triethylenetetramine (318 grams, 2 moles) and methanol (158 grams) wereweighed into a 1-liter resin kettle of the type described in Example 8.The reactor contents were stirred while cooled to 10° C. A methanolicsolution of acrolein was prepared by mixing 102.02 grams distilledacrolein (1.82 moles) with 102.2 grams methanol. The methanolic solutionof acrolein was added dropwise to the methanolic solution oftriethylenetetramine at such a rate that the rise in temperature did notexceed 13° C. Methanol and water were removed from the reactor contentsby rotary evaporation under full vacuum at boiling water temperature.

The resultant triethylenetetramine/acrolein oligomers (99.81 grams),Westvaco Diacid 1550 (223.15 grams, 0.63 mole) and isopropanol (798.02grams) were weighed into a 2-liter resin kettle of the type described inExample 9. The reactor contents were refluxed at 84° C. for 60 minutes(3600 s). Isopropanol and water were removed with a Barrett trap as thereaction temperature was increased from 84° C. to 220° C. The reactorcontents were heated an additional 210 minutes (12,600 s) at 220° C.,cooled to room temperature and dissolved in isopropanol (457.28 grams).

EXAMPLE 12

2-(2-Aminoethylamino)ethanol (418.54 grams, 4.02 moles) and methanol(464.47 grams) were weighed into a 2-liter resin kettle equipped with animmersion thermometer, mechanical stirrer, addition funnel, condenserand nitrogen purge system. The reactor contents were stirred whilecooled to 7° C. A methanolic solution of acrolein was prepared by mixing114.5 grams distilled acrolein (2.04 moles) with 160.9 grams methanol.The methanolic solution of acrolein was added dropwise to the methanolicsolution of 2-(2-aminoethylamino)ethanol over a period of 112 minutes(6720 s) at such a rate that the rise in temperature did not exceed 18°C. The resulting red orange liquid was subjected to rotary evaporationunder full vacuum at boiling water temperature. Isopropanol was added tothe rotary evaporation bottoms, and this mixture was again subjected torotary evaporation under full vacuum at boiling water temperature.

The 2-(2-aminoethylamino)ethanol/acrolein oligomers (87.86 grams),Westvaco Diacid 1550 (142.31 grams, 0.4 mole) and isopropanol (387.57grams) were weighed into a 1-liter resin kettle equipped with animmersion thermometer, mechanical stirrer, condenser and nitrogen purgesystem. The reactor contents were refluxed at 84° C. for one hour (3600s). Then isopropanol and water were removed by using a Barrett trap asthe reaction temperature was increased from 84° C. to 210° C. Thereactor contents were heated an additional 120 minutes (7200 s) at 210°C., cooled to room temperature and dissolved in isopropanol (359.42grams) by refluxing for 60 minutes (3600 s).

EXAMPLE 13

Ethylenediamine (516.78 grams, 8.51 moles) and methanol (451.71 grams)were added to a 3-liter jacketed resin kettle equipped with an immersionthermometer, mechanical stirrer, addition funnel, condenser and nitrogenpurge system. The reactor contents were cooled to 4° C. by pumping achilled aqueous solution of ethylene glycol through the jacket of theresin kettle. A methanolic solution of acrolein was prepared by mixing480.91 grams distilled acrolein (8.32 moles) with 452.9 grams methanol.The methanolic solution of acrolein was added dropwise to the methanolicsolution of ethylenediamine at such a rate that the rise in temperaturedid not exceed 7° C. The reactor contents were subjected to rotaryevaporation under full vacuum at boiling water temperature. Isopropanol(455.52 grams) was added to the rotary evaporation bottoms, and thismixture was again subjected to rotary evaporation under full vacuum atboiling water temperature.

EXAMPLE 14

Ethylenediamine/acrolein oligomers (50 grams) prepared in Example 13,lauric acid (84.7 grams, 0.4235 mole) and isopropanol (202.5 grams) wereweighed into a 1-liter resin kettle equipped with an immersionthermometer, mechanical stirrer, condenser and nitrogen purge system.The reactor contents were refluxed at 84° C. for one hour (3600 s). Thenisopropanol and water were removed by using a Barrett trap as thereaction temperature was increased from 84° C. to 210° C. The reactorcontents were heated an additional 240 minutes (14,400 s) at 210° C.,cooled to room temperature and dissolved in isopropanol by refluxing at84° C. for one hour (3600 s).

EXAMPLE 15

Ethylenediamine/acrolein oligomers (50 grams) prepared in Example 13,tall oil fatty acid (183.1 grams, 0.65 mole) and isopropanol (350 grams)were weighed into a reactor of the type described in Example 13. Thereactor contents were refluxed at 84° C. for one hour (3600 s). Thenisopropanol and water were removed by using a Barrett trap as thereaction temperature was increased from 84° C. to 210° C. The reactorcontents were heated between 84° C. and 210° C. for 230 minutes (13,800s), cooled to room temperature and dissolved in 1-butanol (379 grams) byrefluxing at 84° C. for one hour (3600 s).

EXAMPLE 16

Ethylenediamine (870.49 grams, 14.48 moles) and methanol (758.45 grams)were added to a 4-liter jacketed resin kettle equipped with an immersionthermometer, mechanical stirrer, addition funnel, condenser and nitrogenpurge system. The reactor contents were cooled to -2° C. by pumping achilled aqueous solution of ethylene glycol through the jacket of theresin kettle. A methanolic solution of acrolein was prepared by mixing811.98 grams of distilled acrolein (14.48 moles) with 765.22 gramsmethanol. The methanolic solution of acrolein was added dropwise to themethanolic solution of ethylenediamine over a period of 1165 minutes(69,900 s) and at such a rate that the rise in temperature did notexceed 11° C. The reactor contents were rotary evaporated under fullvacuum at boiling water temperature. Isopropanol was added to the rotaryevaporation bottoms, and this mixture was again rotary evaporated underfull vacuum between 95°-98° C.

The ethylenediamine/acrolein oligomers (50 grams), Empol™ 1003 (147.05grams, 0.25 mole) and isopropanol (296 grams) were weighed into areaotor of the type described in Example 14. Empol™ 1003 is a C₃₆ dimercarboxylic acid which is commercially available from Emery Industries,lnc. The reactor contents were refluxed at 84° C. for one hour (3600 s).Then isopropanol and water were removed by using a Barrett trap as thereaction temperature was increased from 84° C. to 220° C. over a periodof 77 minutes (4620 s). The reactor contents were cooled to roomtemperature and dissolved in isopropanol (323.7 grams) by refluxing at84° C. for one hour (3600 s).

EXAMPLE 17

Ethylenediamine (1004.43 grams, 16.71 moles) and methanol (631.87 grams)were weighed into a 4-liter reactor of the type described in Example 16.A methanolic solution of acrolein was prepared by mixing 965.42 gramsdistilled acrolein (17.24 moles) with 628.14 grams methanol. Themethanolic solution of acrolein was added dropwise to the methanolicsolution of ethylenediamine cooled at 0.8° C. over a period of 1260minutes (75,600 s) and at such a rate that the rise in temperature didnot exceed 8° C. The reactor contents were rotary evaporated under fullvacuum at boiling water temperature. Isopropanol was added to the rotaryevaporation bottoms, and this mixture was again rotary evaporated underfull vacuum at boiling water temperature.

The ethylenediamine/acrolein oligomers (50 grams), Naphthenic Acid(195.5 grams, 0.77 moles) and isopropanol (368 grams) were weighed intoa reactor of the type described in Example 14. Naphthenic Acid is amixture of cyclohexane carboxylic acids which is commercially availablefrom the Exxon Chemical Co. The reactor contents were refluxed at 84° C.for one hour (3600 s). Then isopropanol and water were removed by usinga Barrett trap as the reaction temperature was increased from 84° C. to220° C. The reactor contents were heated between 200° to 220° C. for 185minutes (11,100 s), cooled to room temperature and dissolved inisopropanol (402 grams) by refluxing at 84° C. for one hour (3600 s).

EXAMPLE 18

Ammonium chloride (53.48 grams, 1 mole) and methanol (79.75 grams) wereadded to a 4-neck 250 milliliter round bottom flask equipped with animmersion thermometer, dewar condenser containing a mixture of dry iceand methanol, mechanical stirrer, addition funnel and nitrogen purgesystem. A methanolic solution of acrolein was prepared by mixing 56.16grams distilled acrolein (1 mole) with 47.87 grams methanol. Themethanolic solution of acrolein was added dropwise to the methanolicsolution of ammonium chloride at 58° C. over a period of 105 minutes(6300 s). The reaction temperature was maintained at 58° C. for anadditional 905 minutes (54,300 s). A methanolic solution ofethylenediamine was prepared by mixing 30.18 grams ethylenediamine (0.5mole) with 20.46 grams methanol. The methanolic solution ofethylenediamine was added to the reactor contents at a temperaturebetween 58° C. to 65° C. over a period of 67 minutes (4020 s). Thereaction temperature was maintained between 65° C. and 70° C. for 73minutes (4380 s). A Barrett trap was installed, and methanol and waterwere removed as the reaction temperature was increased from 70° C. to115° C. over a period of 120 minutes (7200 s). The reactor contents werea reddish brown solid after they were cooled to room temperature. Thereddish brown solid was dissolved in methanol for the corrosioninhibition tests.

EXAMPLE 19

The reddish brown solid from Example 18 (50.54 grams), Westvaco Diacid1550 (109.78 grams, 0.31 mole) and isopropanol (235.98 grams) wereweighed into a reactor of the type described in Example 14. The reactorcontents were refluxed at 82° C. for 80 minutes (4800 s) A Barrett trapwas installed and reaction temperature increased from 70° C. to 210° C.as water and isopropanol were removed. The reaction temperature wasmaintained at 210° C. for 225 minutes (13,500 s). The reactor contentswere a brown taffy-like solid after they were cooled to roomtemperature. The brown solid was dissolved in water for the corrosioninhibition tests.

EXAMPLE 20

Ethylenediamine (114.35 grams, 1.9 moles), KEMAMINE™ P-650 (20.28 grams,0.099 mole) and methanol (156.84 g) were weighed into a 1-liter resinkettle of the type described in Example 8. KEMAMINE™ P-650 is a mixtureof C₁₀ -C₁₈ primary amines commercially available from Witco ChemicalCorp. which consists primarily of 1-decanamine, 1-dodecanamine,1-tetradecanamine, 1-hexadecanamine, 1-octadecanamine andoctadecen-1-amine. A methanol solution of acrolein was prepared bymixing 112.07 grams (2 moles) distilled acrolein with 157.58 gramsmethanol. The methanolic solution of acrolein was added dropwise to themethanolic solution of amines over a period of 91 minutes (5460 s) andat a rate that the rise in temperature did not exceed 16° C. The reactorcontents were rotary evaporated under full vacuum at boiling watertemperature. Isopropanol was added to the rotary evaporation bottoms,and this mixture was again rotary evaporated under full vacuum atboiling water temperature.

EXAMPLE 21

The ethylenediamine/KEMAMINE™ P-650/acrolein oligomers (102.45 grams),Westvaco Diacid 1550 (200.6 grams, 0.57 mole) and isopropanol (335.6grams) were weighed into a reactor of the type described in Example 14.The reactor contents were refluxed between 84° C.-85° C. for 66 minutes(3960 s). Then isopropanol and water were removed by using a Barretttrap as the reaction temperature was increased from 84° C. to 211° C.over a period of 108 minutes (6480 s). The reactor contents were heatedbetween 208° C. to 213° C. for 203 minutes (12,180 s), cooled to 150° C.and dissolved in isopropanol (228.53 grams) by refluxing at 84° C. forone hour (3600 s).

EXAMPLE 22

Ethylenediamine (714.04 grams, 11.88 moles) and methanol (547.06 grams,17.07 moles) were added to a 3-liter jacketed resin kettle equipped withan immersion thermometer, mechanical stirrer, nitrogen purge system andcondenser. The reactor contents were cooled between 5° C. and 10° C. bypumping a chilled aqueous solution of ethylene glycol through thejacket. A methanolic solution of acrolein was prepared by mixing 667.53grams distilled acrolein (11.91 moles) with 623.97 grams methanol (19.47moles). The methanolic solution of acrolein was pumped from a reservoirat a rate of 2 milliliters of the methanolic solution of acrolein perminute through a 0.5-1 mm i.d. stainless steel transfer line orientedfor subsurface addition into the methanolic solution of ethylenediaminewith a Milton Roy pump. The acrolein was added to the reactor over aperiod of 794 minutes (47,640 s) at a temperature between -2° C. and 6°C. The reactor contents were subjected to rotary evaporation under fullvacuum at boiling water temperature. Isopropanol (300 milliliters) wasadded to the rotary evaporation bottoms and this mixture was againsubjected to rotary evaporation under full vacuum at boiling watertemperature. The resulting ethylenediamine/acrolein oligomers (506.11grams) were dissolved in isopropanol (740.12 grams).

EXAMPLE 23

The isopropanol solution (73.05 grams) of 68.38 weight percentethylenediamine/acrolein oligomers prepared in Example 22, oleic acid(128.79 grams, 0.46 mole) and isopropanol (156.05 grams) were weighedinto a reactor of the type described in Example 14. The reactor contentswere refluxed at 84° C. for 1 hour (3600 s) and then cooled to roomtemperature giving an isopropanol solution of 50 weight percent salt ofoleic acid with ethylenediamine/acrolein oligomers.

EXAMPLE 24

A Barrett trap was attached to the reactor of Example 23 and isopropanoland water removed as the reaction temperature was increased from 25° C.to 210° C. over a period of 140 minutes (8400 s). The reactor contentswere heated at 210° C. for 295 minutes (17,700 s) and then cooled toroom temperature giving a black viscous liquid. The black viscous liquidwas dissolved in isopropanol for the corrosion inhibition tests.

EXAMPLE 25

The isopropanol solution of 68 weight percent ethylenediamine/acroleinoligomers (35.43 grams) prepared in Example 22 and methanol (59.95grams) were weighed into a 500 milliliter resin kettle equipped with animmersion thermometer, mechanical stirrer, nitrogen purge system andcondenser. 1-Bromooctadecane (73.58 grams, 0.22 mole) was added to thereactor contents. The reactor contents were refluxed for 61 minutes(3660 s) between 69° C.-75° C. A Barrett trap was installed and methanoland isopropanol were removed as the reaction temperature was increasedfrom 69° C. to 210° C. over a period of 211 minutes (12,660 s). Thereactor contents were heated an additional 345 minutes (20,700 s)between 210° C.-250° C. and then cooled to room temperature.

EXAMPLE 26

The product from the reaction of ethylenediamine/acrolein oligomers with1-bromooctadecane described in Example 25 (24.27 grams), water (75milliliters) and an aqueous solution of 58.61% sodium hydroxide (7.15grams) were stirred at 90° C. for 10 minutes (600 s). After the mixturewas cooled to room temperature, the mixture was extracted withdiethylether and chloroform. The diethylether and chloroform extractswere subjected to rotary evaporation under full vacuum giving a blackviscous liquid. The black liquid was mixed with isopropanol and theisopropanol removed by rotary evaporation under full vacuum.

EXAMPLE 27

Ethyleneamine E-100 (1127.27 grams) and methanol (617.52 grams) wereadded to the 4-liter resin kettle of the type described in Example 16. Amethanolic solution of acrolein was prepared by mixing 441.72 gramsdistilled acrolein (7.88 moles) with 386.02 grams methanol. The acroleinwas pumped into the reactor over a period of 507 minutes (30,435 s) at atemperature between 3° C. and 6° C. The reactor contents were subjectedto rotary evaporation under full vacuum at boiling water temperature.Isopropanol (300 milliliters) was added to the rotary evaporationbottoms and this mixture was again subjected to rotary evaporation underfull vacuum at boiling water temperature.

The Ethyleneamine E-100/acrolein oligomers (50.31 grams), methanol(102.83 grams) and 1-bromooctadecane (185.23 grams, 0.56 mole) wereweighed into a 500 milliliter reactor of the type described in Example25. The reactor contents were refluxed for 78 minutes (4680 s) at 70° C.A Barrett trap was installed and methanol was removed as the reactiontemperature was increased from 70° C. to 200° C. over a period of 90minutes (5400 s). The reactor contents were heated an additional 5minutes (300 s) between 200° C. to 210° C. and then cooled to roomtemperature. The resulting brown solid was dissolved in xylene for thecorrosion inhibition tests.

EXAMPLE 28

The product from the reaction of Ethyleneamine E-100/acrolein oligomerswith 1-bromooctadecane described in Example 27 (50.18 grams) and anaqueous solution of 34% sodium hydroxide (152.37 grams) were stirredwhile warming on a hot plate until complete dissolution. After themixture was cooled to room temperature, the mixture was extracted withdiethylether (200 milliliters). The diethylether extract was subjectedto rotary evaporation under full vacuum. The resulting rotaryevaporation bottoms were extracted with chloroform (300 milliliters).The chloroform extract was subjected to rotary evaporation under fullvacuum giving a dark brown solid. The dark brown solid was dissolved inxylene for the corrosion inhibition tests.

COMPARATIVE EXPERIMENT A

Diethylenetriamine (51.23 grams, 0.5 mole) and benzene (27.64 grams,0.35 mole) were weighed into a 4-neck 250 milliliter round bottom flaskequipped with an immersion thermometer, condenser, mechanical stirrer,nitrogen purge system and addition funnel. Benzaldehyde (48.5 grams,0.46 mole) was added slowly to the reactor contents between 85° C. to89° C. during a 75 minute (4500 s) period. Benzene and water wereremoved with a Barrett trap, as the reaction temperature was increasedto 190° C. over a period of 45 minutes (2700 s). The reactor contentswere heated for an additional 2 hours (7200 s) at 190° C. The reactorcontents were cooled to room temperature and benzene (31.88 grams) addedto them. Heptaldehyde (43.32 grams, 0.38 mole) was added slowly to thereactor contents at 80° C. over a 65 minute (3900 s) period. Benzene andwater were removed with a Barrett trap, as the reaction temperature wasincreased to 190° C. over a period of 43 minutes (2580 s). The reactorcontents were heated for an additional 2 hours (7200 s) at 190° C.

COMPARATIVE EXPERIMENT B

The final product (25.06 grams) from Comparative Experiment A and oleicacid (17.26 grams, 0.06 mole) were weighed into a reactor of the typedescribed in Comparative Experiment A. The reactants were heated between80° C.-120° C. for 55 minutes (3300 s) and then cooled to roomtemperature.

COMPARATIVE EXPERIMENT C

Ethylenediamine (21.9 grams, 0.36 mole) and benzene (28.37 grams, 0.36mole) were weighed into a reactor of the type described in ComparativeExperiment A. Benzaldehyde (38.72 grams, 0.36 mole) was added slowly tothe reactor contents at 85° C. over a 32 minute (1920 s) period. Benzeneand water were removed with a Barrett trap as the reaction temperaturewas increased to 190° C. over a 73 minute (4380 s) period. The reactorcontents were heated for an additional 2 hours (7200 s) at 190° C. Thereactor contents were cooled to room temperature and benzene (28.22grams) added to them. Heptaldehyde (21.65 grams, 0.19 mole) was addedslowly to the reactor contents at 80° C. over a 39 minute (2340 s)period. Benzene and water were removed with a Barrett trap, as thereaction temperature was increased to 190° C. over a 52 minute (3120 s)period. The reactor contents were heated for an additional 2 hours (7200s) at 190° C.

COMPARATIVE EXPERIMENT D

Diethylenetriamine (85 grams, 0.83 mole) and benzene (42.12 grams) wereweighed into a reactor of the type described in Comparative ExperimentA. A 37% aqueous solution of formaldehyde (61.06 grams, 0.75 mole) wasadded slowly to the reactor contents between 68° C.-70° C. over a 195minute (11,700 s) period. Benzene and water were removed with a Barretttrap as the reaction temperature was increased to 190° C. over a periodof 126 minutes (7560 s). The reactor contents were cooled to 100° C.,and heptaldehyde (85.64 grams, 0.75 mole) was added slowly to thereactor contents between 95° C.-100° C. over a 50 minute (3000 s)period. Benzene and water were removed with a Barrett trap, as thereaction temperature was incrementally increased to 190° C. over a 25minute (1500 s) period. The reactor contents were heated an additional 3hours 20 minutes (12,000 s) at 190° C.

COMPARATIVE EXPERIMENT E

The final product (25 grams) from Comparative Experiment D and oleicacid (23.46 grams, 0.08 mole) were weighed into a reactor of the typedescribed in Comparative Experiment A. The reactants were heated between80° C.-100° C. for 65 minutes (3900 s) and then cooled to roomtemperature.

COMPARATlVE EXPERIMENT F

A benzyl chloride quaternized aminoamide polymer was prepared accordingto the procedure of Example 6 in U.S. Pat. No. 4,315,087 by Redmore andOutlaw.

PREPARATION OF CORROSION INHIBITOR FOR EVALUATION IN ZINC/CALCIUMBROMIDE CLEAR BRINE FLUID TEST, 250° F. (121.11° C.) EXAMPLE 29

Ethylenediamine (872.07 grams, 14.51 moles) and methanol (759.30 grams)were weighed into a reactor of the type described in Example 16. Thereactor contents were stirred while cooled to -10° C. A methanolicsolution of acrolein was prepared by mixing 856.11 grams distilledacrolein (15.27 moles) with 764.60 grams methanol. The methanolicsolution of acrolein was pumped from a reservoir at a rate of 2.25milliliters of the methanolic solution of acrolein per minute through a0.5-1 mm i.d. stainless steel transfer line oriented for subsurfaceaddition into the methanolic solution of ethylenediamine with a MiltonRoy pump. The reaction product was subjected to rotary evaporation underfull vacuum at boiling water temperature. Isopropanol (305.05 grams) wasadded to the rotary evaporation bottoms and this mixture was againsubjected to rotary evaporation under full vacuum again at boiling watertemperature.

The ethylenediamine/acrolein oligomers (50.56 grams), Westvaco Diacid1550 (86.42 grams, 0.25 mole) and isopropanol (175.88 grams) wereweighed into a 500 milliliter reactor of the type described in Example25. The reactor contents were refluxed for 60 minutes (3600 s) at 82° C.and then cooled to room temperature giving an isopropanol solution of44% salt of Westvaco Diacid 1550 with ethylenediamine/acroleinoligomers. Infrared spectroscopy supported the presence of the salt witha strong band at 1555 cm⁻¹ and a weaker band at 1397 cm⁻¹.

PREPARATION OF CORROSION INHIBITORS FOR EVALUATION IN HYDROCHLORIC ACIDSTIMULATION TEST, 175° F. (79.4° C.) EXAMPLE 30

Ethylenediamine (100 grams, 1.66 moles) and methanol (500 milliliters)were added to a 2-liter resin kettle of the type described in Example 1.The reactor contents were stirred while cooled to less than 5° C. withan ice-water bath. Distilled acrolein (88 grams, 1.58 moles) was addeddropwise to the methanolic solution of ethylenediamine. The reactorcontents were rotary evaporated under full vacuum at boiling watertemperature. Toluene was added to the rotary evaporator bottoms, andthis mixture was rotary evaporated under full vacuum at boiling watertemperature giving a viscous, wax-like solid. Infrared spectroscopysupports the presence of NH, NH₂, imine (C=N) and ether groups. CHNanalysis indicated the ethylenediamine/acrolein oligomers contained 62.1wt. % carbon, 22.6 wt. % nitrogen, 10.6 wt. % hydrogen and 4.7 wt. %oxygen.

EXAMPLE 31

Ethylenediamine (99.5 grams, 1.66 moles) and methanol (386.6 grams) wereweighed into a reactor of the type described in Example 1. The reactorcontents were stirred while cooled to 2° C. with an ice-water bath. Amethanolic solution of acrolein was prepared by mixing 120.6 gramsdistilled acrolein (2.15 moles) with 165 grams methanol. The acroleinwas distilled in the presence of 342 and 368 ppm hydroquinone in theboiling and receiver flasks, respectively. The methanolic solution ofacrolein was added dropwise to the methanolic solution ofethylenediamine over a period of 108 minutes (6480 s) at such a ratethat the rise in temperature did not exceed 15° C. The reactor contentswere rotary evaporated under full vacuum at boiling water temperature.Isopropanol was added to the rotary evaporator bottoms, and this mixturewas rotary evaporated under full vacuum at boiling water temperature.The resultant ethylenediamine/acrolein oligomers was a mixture of awhite crystalline solid and a yellow viscous liquid.

EXAMPLE 32

Ethylenediamine (100.1 grams, 1.67 moles) and methanol (387.9 grams)were weighed into a reactor of the type described in Example 1. Thereactor contents were stirred in a nitrogen atmosphere while cooled to2° C. with an ice-water bath. A methanolic solution of distilledacrolein was prepared by mixing 129.8 grams distilled acrolein (2.32moles) with 153.9 grams methanol. The acrolein was distilled in thepresence of 402 and 374 ppm of hydroquinone in the boiling and receiverflasks, respectively. The methanolic solution of acrolein was addeddropwise to the methanolic solution of ethylenediamine over a period of75 minutes (4500 s) at such a rate that the rise in temperature did notexceed 20° C. Twenty minutes after the acrolein addition was complete,the reactor contents reached maximum viscosity at room temperaturegiving a rubberlike solid. This solid was grounded with a mortar andpestle. Isopropanol was added to the grounded solid and rotaryevaporated under full vacuum at boiling water temperature.

EXAMPLE 33

Diethylenetriamine (206 grams, 2 moles) and methanol (390.5 grams) wereweighed into a reactor of the type described in Example 1. The reactorcontents were stirred in a nitrogen atmosphere while cooled to 0.5° C.with an ice-water bath. A methanolic solution of acrolein was preparedby mixing 181.4 grams distilled acrolein (3.24 moles) with 155.3 gramsmethanol. The methanolic solution of acrolein was added dropwise to themethanolic solution of diethylenetriamine over a period of 110 minutes(6600 s) at such a rate that the rise in temperature did not exceed 19°C. The reactor contents were rotary evaporated under full vacuum atboiling water temperature. Isopropanol was added to the rotaryevaporator bottoms, and this mixture was rotary evaporated under fullvacuum at boiling water temperature giving a mixture of a whitecrystalline solid and clear viscous liquid. Only the clear viscousliquid was tested as a corrosion inhibitor.

EXAMPLE 34

Ethyleneamine E-100 (245 grams, 1 mole) and methanol (386 grams) wereweighed into a reactor of the type described in Example 1. The reactorcontents were stirred in a nitrogen atmosphere while cooled to -1° C.with an ice-water bath. A methanolic solution of acrolein was preparedby mixing 74.7 grams distilled acrolein (1.33 moles) with 157.7 gramsmethanol. The methanolic solution of acrolein was added dropwise to themethanolic solution of Ethyleneamine E-100 over a period of 67 minutes(4020 s) at such a rate that the rise in temperature did not exceed 8°C. The reactor contents were rotary evaporated under full vacuum atboiling water temperature giving a viscous liquid.

EXAMPLE 35

The product from the reaction of Epoxide 8 with ethylenediamine/acroleinoligomers (43.6 grams) described in Example 2 was mixed with isopropanol(65.9 grams) in a reactor of the type described in Example 1. Thereactor contents were heated to 85° C. while stirring in a nitrogenatmosphere.

EXAMPLE 36

Propargyl alcohol (0.39 gram) was mixed with the cooled isopropanolsolution (3.85 grams) of the product from the reaction of Epoxide 8 withethylenediamine/acrolein oligomers described in Example 35.

EXAMPLE 37

An aqueous solution of 37% formaldehyde (14.6 grams, 0.49 mole) wasadded to the isopropanol solution of the product (37 grams) from thereaction of Epoxide 8 with ethylenediamine/acrolein oligomers describedin Example 35 over a period of 24 minutes (1440 s) while the reactiontemperature was maintained between 83° C. and 85° C. Isopropanol (100milliliters) was added to the reactor contents after they were cooled to56° C. The reactor contents were heated until they refluxed (85° C.) andthen cooled to room temperature. Isopropanol and water were removed byrotary evaporation under full vacuum at boiling water temperature.

EXAMPLE 38

The product from the reaction of formaldehyde and Epoxide 8 withethylenediamine/acrolein oligomers (75.6 grams) described in Example 37and isopropanol (88 grams) were weighed into a reactor of the typedescribed in Example 1. The reactor contents were heated to the refluxtemperature and then cooled to room temperature. Propargyl alcohol (3.6grams) was added to the reactor contents (33.7 grams).

EXAMPLE 39

The product from the reaction of formaldehyde and Epoxide 8 withethylenediamine/acrolein oligomers in isopropanol after mixing withpropargyl alcohol described in Example 38 (24.5 grams) was mixed furtherwith an aqueous solution of 37% formaldehyde (11.1 grams, 0.37 mole).

EXAMPLE 40

Propargyl alcohol (11.6 grams) was mixed at room temperature with theisopropanol solution (89 grams) of 37.9 weight percent product from thereaction of Westvaco Diacid 1550 with ethylenediamine/acrolein oligomersdescribed in Example 4.

EXAMPLE 41

The onset of thermal decomposition of various corrosion inhibitorchemistries in a nitrogen atmosphere was determined by thermal analysistechniques including Differential Scanning Calorimetry (DSC) and ThermalGravimetric Analysis (TGA) with a Dupont 1090 Thermal Analyzer. Anexotherm associated with weight loss was determined as the onset ofdegradation. In the Differential Scanning Calorimetry analysis, thesamples were placed in an aluminum pan and programmed from 25° C. to500°0 C. at 10° C./minute (0.167° C./s) with a nitrogen purge. In theThermal Gravimetric Analysis, the samples were placed in a platinum panand programmed from 25° C. to 500° C. at 10° C./minute (0.167° C./s)with a nitrogen purge. Samples included the reaction product ofethylenediamine, acrolein and Westvaco Diacid 1550 described in Example4, two commercially available corrosion inhibitors and corrosioninhibitors prepared in U.S. Pat. Nos. 2,643,977 and 4,315,087. Resultsare presented in Table I.

                  TABLE I                                                         ______________________________________                                                        Proposed                                                                      Decomposition                                                                 Temperature                                                   Sample          (°C.)                                                  ______________________________________                                        Ex. 4           420                                                           Corban A-162.sup.1 *                                                                          300                                                           Textamine T5D.sup.2 *                                                                         350                                                           Comp. Expt. D*  200                                                           Comp. Expt. E*  275                                                           Comp. Expt. F*  250                                                           ______________________________________                                         *Not an example of the present invention.                                     .sup.1 Corban A162 is a commercial corrosion inhibitor available from         DowellSchlumberger.                                                           .sup.2 Textamine T5D is a commercial corrosion inhibitor available from       Henkel as Textamine T5D.                                                 

The data of Table I indicates that the corrosion inhibitor os thisinvention has a superior thermal stability to those corrosion inhibitorswhich are commercially available and the corrosion inhibitors in U.S.Pat. Nos. 2,643,977 and 4,315,087.

EXAMPLE 42

Corrosion inhibition of various samples was determined under conditionswhich simulate conditions that exist in oil and gas wells as follows. Abrine solution containing 89.89 percent deionized water, 9.62 percentsodium chloride, 0.305 percent calcium chloride and a 0.186 percenthydrated magnesium chloride complex was prepared. This brine solutionwas saturated under carbon dioxide purge until a pH of 3.8 was achieved.The solution was treated with sodium sulfite to remove oxygen Thedesired corrosion inhibitor was added to the solution. About 720milliliters (ml) of this brine solution and 80 ml of kerosene treatedwith sodium sulfite were charged into a 32-ounce bottle. To this chargewas added enough hydrated sodium sulfide to generate a suitable amountof hydrogen sulfide (i.e., about 300 ppm hydrogen sulfide based on totalfluids).

Metal coupons (12"×1/4"×1/16", 304.8 mm×6.35 mm×1.59 mm) of 1020 carbonsteel were degreased with an inhibited methylchloroform, acidized with16 percent hydrochloric acid, washed and dried. Each coupon weighedabout 19 g. A metal coupon was placed in the bottle containing thebrine, kerosene and ingredients as previously described. The bottle wascapped and acetic acid was injected into the bottle through a septum.The bottle was placed on a vertically rotating wheel held at 175° C.(79.4° C.) and the sample was rotated at 26 rpm for 24 hours (86,400 s).The coupons were removed from the bottle, cleaned, washed, dried andreweighed.

The percent protection afforded them by the inhibitor was calculated asthe percent protection by the following formula: ##EQU1## Corrosionrates were determined in milliinches per year (mpy) by the followingformula: ##EQU2## d=density of 1020 carbon steel=7.86 g/ml a=surfacearea (in².) of metal coupons

t=test time in hours

The amount of corrosion of untreated coupons were compared to couponswhich were tested in the presence of 100 ppm of each corrosion inhibitorsample. Results are presented in Table II.

                  TABLE II                                                        ______________________________________                                        80° C. Wheel Test                                                                                        Corro-                                                        Concen-   Weight                                                                              sion                                                          tration   Loss  Rate   % Pro-                               Test Inhibitor    (ppm)     (grams)                                                                             (MPY*) tection                              ______________________________________                                        A    None*        0         0.0336                                                                              14.1   0                                         Ex. 2        100       0.0051                                                                              2.1    85                                   B    None*        0         0.0810                                                                              34.1   0                                         Ex. 3        100       0.0126                                                                              5.2    84                                        Ex. 4        100       0.0133                                                                              5.5    84                                        Ex. 6        100       0.0178                                                                              7.4    78                                   C    None*        0         0.1766                                                                              64.1   0                                    D    None*        0         0.1004                                                                              36.2   0                                         Ex. 7        100       0.0102                                                                              3.7    90                                   E    None*        0         0.1674                                                                              61.1   0                                         Ex. 8        100       0.0076                                                                              2.7    96                                        Ex. 9        100       0.0144                                                                              5.1    91                                   F    None*        0         0.2014                                                                              74.1   0                                         Ex. 10       100       0.0363                                                                              13.1   82                                        Ex. 11       100       0.0112                                                                              4.0    94                                   G    None*        0         0.2326                                                                              93.7   0                                         Ex. 14       100       0.0162                                                                              6.8    93                                   H    None*        0         0.1555                                                                              63.6   0                                         Ex. 15       100       0.0064                                                                              2.6    96                                   I    None*        0         0.1774                                                                              72.0   0                                         Ex. 16       100       0.0088                                                                              3.6    95                                   J    None*        0         0.2063                                                                              79.6   0                                         Ex. 17       100       0.0145                                                                              5.6    93                                   K    None*        0         0.1916                                                                              72.9   0                                         Ex. 18       100       0.0981                                                                              36.7   49                                   L    None*        0         0.1733                                                                              65.7   0                                         Ex. 19       100       0.0087                                                                              3.3    95                                        Ex. 23       100       0.0282                                                                              10.7   84                                        Ex. 24       100       0.0033                                                                              1.3    98                                   M    None*        0         0.1496                                                                              58.0   0                                         Ex. 20       100       0.0408                                                                              3.6    94                                   N    None*        0         0.2542                                                                              97.9   0                                         Ex. 21       100       0.0141                                                                              5.5    94                                   O    None*        0         0.1808                                                                              68.2   0                                         Ex. 25       100       0.0065                                                                              2.5    96                                   P    None*        0         0.1701                                                                              65.8   0                                         Ex. 26       100       0.0048                                                                              1.8    97                                        Ex. 28       100       0.0082                                                                              3.2    95                                   Q    None*        0         0.1819                                                                              70.1   0                                         Ex. 27       100       0.0088                                                                              3.4    95                                   R    None*        0         0.2077                                                                              80.6   0                                         Comp. Expt. A*                                                                             100       0.0028                                                                              1.1    99                                        Comp. Expt. D*                                                                             100       0.0056                                                                              2.1    97                                   S    None*        0         0.1912                                                                              73.1   0                                         Comp. Expt. B*                                                                             100       0.0054                                                                              2.1    97                                        Comp. Expt. C*                                                                             100       0.0029                                                                              1.1    99                                   T    None*        0         0.1721                                                                              65.6   0                                         Comp. Expt. D                                                                              100       0.0050                                                                              1.9    97                                   U    None*        0         0.1701                                                                              65.8   0                                         Comp. Expt. E*                                                                             100       0.0159                                                                              6.1    91                                   V    None*        0         0.3328                                                                              131.0  0                                         Corban A-163*.sup.2                                                                        100       0.0658                                                                              26.0   80                                   ______________________________________                                         *Not an example of the present invention.                                     .sup.1 MPY is mils per year                                                   .sup.2 Corban A163 is a commercial corrosion inhibitor available from         DowellSchlumberger                                                       

The data in Table II indicates that the samples of this inventionexhibit good corrosion inhibition under simulated down hole tests. Thecorrosion inhibition of the samples of this invention is comparable tothat exhibited by commercially available corrosion inhibitors and thecorrosion inhibitors in U.S. Pat. No. 2,643,977 by Hughes and U.S. Pat.No. 4,315,087 by Redmore and Outlaw.

EXAMPLE 43

The corrosion protection afforded by various corrosion inhibitors isoften improved by the presence of hydrogen sulfide. In other words, thecorrosion inhibition of an inhibitor in non-hydrogen sulfideenvironments (sweet) is 10-20 percent less than the corrosion protectionachieved in otherwise similiar hydrogen sulfide environments. It is acommon practice to alleviate this problem by incorporating sulfur orsulfur containing compounds into a formulated corrosion inhibitor byadding, for example, thiourea, dimethylsulfate, trithiones, and thelike. This example demonstrates the performance of the inhibitors ofthis invention in non-hydrogen sulfide environments via a 175° F. testexcluding hydrogen sulfide. Results are presented in Table III. Thenumbers in parenthesis are the results of the same inhibitor in asimiliar test containing hydrogen sulfide.

                  TABLE III                                                       ______________________________________                                                                      Corro-                                                                        sion                                            Inhibitor                                                                            Con-      Weight Loss  Rate   %                                        Sample centration                                                                              (grams)      (MPY**)                                                                              Protection                               ______________________________________                                        None*  0             0.1184 (0.0810)                                                                          43     0                                                                      (34.1)                                        Ex. 3  100    ppm    0.0196 (0.0126)                                                                          7      83   (84)                                                              (5.2)                                         Ex. 4  100    ppm    0.0122 (0.0133)                                                                          4      90   (84)                                                              (5.5)                                         ______________________________________                                         *Not an example of the present invention.                                     **MPY is mils per year.                                                  

These results indicate that the inhibitors of this invention performnearly equally in hydrogen sulfide or non-hydrogen sulfide and carbondioxide brine environments. Thus, the inhibitors of this inventionadvantageously provide good corrosion protection in sweet and/or sourdown hole oil and gas well environments and require no specialformulating for non-hydrogen sulfide environments.

EXAMPLE 44

The following example demonstrates the performance of the inhibitors ofthis invention in a 350° F. wheel test containing 90 percent brine/8percent heptane/2 percent kerosene at 2,000 psi pressure (25° C.) with10 percent hydrogen sulfide, 10 percent carbon dioxide and 80 percentmethane in a stainless steel pipe bomb. The sample was rotated at 26 rpmfor 24 hours (86,400 s). Metal coupons (6"×1/4"×1/16", 152.4 mm×6.35mm×1.59 mm) of 1020 carbon steel were degreased with chlorothene,scrubbed, washed with acetone and dried before being placed in the pipebomb. After the test, the coupons were removed from the pipe bomb,scrubbed, washed with acetone and dried. The percent protection providedby the inhibitor was calculated by using the folloing formula: ##EQU3##The weight loss was given to the nearest whole percent. The testswherein no inhibitor was employed were for comparative purposes and weredesignated as blanks.

                  TABLE IV                                                        ______________________________________                                        177° C. Wheel Test                                                                        Concen-   Weight                                                              tration   Loss   %                                         Test  Inhibitor    (ppm)     (grams)                                                                              Protection                                ______________________________________                                        A     None*        0         0.1082 0                                               Ex. 2        100       0.0630 42                                              Ex. 4        100       0.0197 82                                        B     None*        0         0.1302 0                                               Ex. 8        100       0.0137 90                                              Ex. 9        100       0.0161 88                                        C     None*        0         0.1432 0                                               Ex. 10       100       0.0171 84                                              Ex. 11       100       0.0180 83                                              Ex. 12       100       0.0191 85                                        D     None*        0         0.1582 0                                               Ex. 14       100       0.0300 82                                              Ex. 15       100       0.0266 84                                        E     None*        0         0.1302 0                                               Ex. 16       100       0.0165 88                                        F     None*        0         0.1192 0                                               Ex. 17       100       0.0113 91                                        G     None*        0         0.1437 0                                               Ex. 20       100       0.0429 71                                              Ex. 21       100       0.0269 82                                        H     None*        0         0.0997 0                                               Ex. 26       100       0.0307 69                                        I     None*        0         0.1022 0                                               Ex. 28       100       0.0213 79                                        J     None*        0         0.1000 0                                               Comp. Expt. A*                                                                             100       0.096  22                                              Comp. Expt. B*                                                                             100       0.035  65                                              Comp. Expt. C*                                                                             100       0.035  64                                              Comp. Expt. D*                                                                             100       0.037  63                                              Comp. Expt. E*                                                                             100       0.040  60                                              Comp. Expt. F*                                                                             100       0.080  20                                        K     None*        0         0.1082 0                                               Corban A-163.sup.1                                                                         100       0.0246 77                                              Textamine T5D.sup.2                                                                        100       0.0485 55                                        ______________________________________                                         .sup.1 Corban A163 is a commercial corrosion inhibitor available from         DowellSchlumberger.                                                           .sup.2 Textamine T5D is a commercial corrosion inhibitor available from       Henkel as Textamine T5D.                                                 

Except for the C₁₂ -C₁₄ glycidyl ether derivative of theethylenediamine/acrolein oligomers from Example 2, the inhibitors ofthis invention advantageously provide good corrosion protection at 350°F., demonstrating the value of these inhibitors for high temperature oiland gas well environments. The corrosion inhibition of the organiccarboxylic acid derivatives of the amine/acrolein oligomers issurprisingly high as compared to commercially available corrosioninhibitors (Corban A-163 and Textamine T5D) and the corrosion inhibitorsin U.S. Pat. Nos. 2,643,977 and 4,315,087.

ZINC/CALCIUM BROMIDE CLEAR BRINE FLUIDS TESTING, 250° F. (121.11° C.)EXAMPLE 45

Corrosion inhibition of the salt of Westvaco dicarboxylic acid withethylenediamine/acrolein oligomers prepared in Example 29 was determinedunder conditions which simulate conditions that exist in oil and gaswells where dense clear brine fluids are used as completion and workoverfluids. The inhibitor was weighed into a 4-ounce glass bottle and then119 grams of 19.3 pound/gallon zinc bromide-calcium bromide solution wasadded. The bottle was capped and heated at 250° F. (121.11° C.) withshaking to disperse or dissolve the inhibitor. Then a cleaned weighedcoupon (25/16"×15/16"×5/32", 39.69 mm×23.81 mm×3.97 mm) of 2 3/8" o.d.quartered N-80 steel pipe was added and the recapped bottle placed in anoven for 168 hours (604,800 s) at 250° F. The coupons were removed fromthe bottle, cleaned in 5% hydrochloric acid inhibited with 0.1% A-120for ten minutes (600 s), scrubbed, rinsed and dried with acetone. A-120is a commercial acid stimulation corrosion inhibitor available fromDowell Schlumberger. The corrosion rate was calculated in milliinchesper year (mpy) by using the following formula:

    mpy=96.89×(gram weight loss of coupon)

The percent protection was calculated by using the same formula as inthe 175° F. corrosion test. The corrosion protection provided by Example29 in the zinc bromidecalcium bromide clear brine fluid test procedureat 250° F. (121.11° C.) is given in Table V.

                  TABLE V                                                         ______________________________________                                               Concen-   Weight    Corrosion                                          Inhibitor                                                                            tration   Loss      Rate     %                                         Sample (ppm)     (grams)   (MPY)    Protection                                ______________________________________                                        None*    0       1.0957    172.0     0                                        Ex. 29 4800      0.2737     43.0    75                                        ______________________________________                                         *Not an example of the present invention                                 

The data in Table V demonstrates the brine soluble inhibitors of thisinvention are suitable for the protection of metal alloys againstcorrosion in dense clear brine fluids used as completion and workoverfluids in oil and gas wells.

HYDROCHLORIC ACID STIMULATION TESTING, 175° F. (79.4° C.) EXAMPLE 46

Corrosion inhibition of various samples was determined under conditionswhich simulate conditions that exist in oil and gas wells during acidstimulation of a rock formation. Metal coupons of 1010 carbon steel wereacidized with 18.5% hydrochloric acid, washed and dried. Two-tenths of apercent of the inhibitor, coupon and 100 grams of 10% hydrochloric acidwere added to a test tube which was placed in one-liter Parr bomb andheated for 6 hours at 175° F. (79.4° C.). The coupon was removed fromthe Parr bomb, cleaned with 18.5% hydrochloric acid which was inhibitedwith A-120, washed and dried. The corrosion rate in milliinches per year(mpy) and percent protection were calculated using the same equations asin the 175° F. corrosion tests. The corrosion protection provided byExamples 2, 4 and 30 through 40 by the hydrochloric acid stimulationtest procedure at 175° F. (79.4° C.,) are given in Table VI.

                  TABLE VI                                                        ______________________________________                                                                        Corro-                                                       Concen-   Weight sion                                                Inhibitor                                                                              tration   Loss   Rate   %                                      Test  Sample   (ppm)     (grams)                                                                              (MPY*) Protection                             ______________________________________                                        A     None*      0       7.6899 16,063 0                                            Ex. 30   2000      0.7637 1,595  90                                     B     None*      0       8.3323 17,404 0                                            Ex. 31   2000      0.5388 1,125  94                                           Ex. 32   2000      0.6100 1,274  93                                     C     None*      0       8.2214 14,310 0                                            Ex. 33   2000      0.7697 1,339  91                                           Ex. 34   2000      0.6239 1,085  92                                     D     None       0       7.8649 13,690 0                                            Ex. 2    2000      0.4703 818    94                                           Ex. 37   2000      0.3952 687    95                                           Ex. 4    2000      0.7166 1,247  91                                           Ex. 40   2000      0.4404 766    94                                     E     None*      0       8.0236 13,966 0                                            Ex. 36   2000      0.6107 1,062  92                                           Ex. 38   2000      0.4951 861    94                                           Ex. 39   2000      0.3326 578    96                                     F     None       0       8.3323 17,404 0                                            A-120.sup.1 *                                                                          2000      0.2030 423    98                                     ______________________________________                                         *Not an example of the present invention                                      .sup.1 A120 is a commercial corrosion inhibitor available from                DowellSchlumberger.                                                      

The data in Table VI demonstrates that the corrosion inhibitors of thisinvention especially those of Examples 37 and 39 provide protection of10% hydrochloric acid comparable to that provided by commerciallyavailable A-120. Therefore, the corrosion inhibitors of this inventionare suitable for the protection of metal alloys against corrosion in oiland gas well formations due to acid stimulation chemicals. In addition,the corrosion inhibitors of this invention are suitable for protectionof metal alloys during steel pickling operations.

What is claimed is:
 1. A new composition of matter which is the reactionproduct resulting from reacting at a temperature of from about 25° C. toabout 250° C. for a time sufficient to complete the reaction asdetermined by halide or residual acid number titrations,(1) the productresulting from reacting, in the presence or absence of a suitablesolvent,(A) at least one aliphatic α,β-monoethylenically unsaturatedaldehyde having from about 3 to about 6 carbon atoms; and (B) at leastone organic polyamine represented by the formula ##STR6## wherein R is adivalent saturated C₂ to C₄ aliphatic hydrocarbon group; each R¹ and R²is independently hydrogen or a saturated alkyl amino or an alkyloxygroup containing from 2 to about 4 carbon atoms or when two adjacent R²groups are taken together, they form a bridging alkylene radicalcontaining 2 carbon atoms such that the R group containing 2 carbonatoms and two adjacent R² groups and two nitrogen atoms form aheterocyclic ring containing 4 carbon atoms and 2 nitrogen atoms; x hasa value from 1 to about 8 andwherein components (A) and (B) are employedin a mole ratio of (A) to (B) of from about 1:1 to about 1:6; and(II)(A) at least one saturated or unsaturated, cyclic or acyclicaliphatic mono- or polycarboxylic acid having from about 2 to about 50carbon atoms; or (B) at least one saturated or unsaturated, cyclic oracyclic aliphatic alkyl monohalide or alkyl polyhalide having from about2 to about 50 carbon atoms; or (C) a combination of (A) and (B);whereincomponents (I) and (II) are employed in quantities which provide fromabout 0.4 to about 1 equivalent of carboxyl and/or halide groups fromcomponent (II) for each theoretically active amino hydrogen atomcontained in component (I).
 2. A composition of claim 1 wherein(a)component (II) has from about 12 to about 36 carbon atoms; and (b)components (I) and (II) are employed in quantities which provide fromabout 0.55 to about 0.85 equivalent of carboxyl and/or halide groupsfrom component (II) for each theoretically active amino hydrogen atomcontained in component (I).
 3. A composition of claim 2 wherein(a)component (II) has from about 16 to about 20 carbon atoms; and (b)components (I) and (II) are employed in quantities which provide fromabout 0.65 to about 0.75 equivalent of carboxyl and/or halide groupsfrom component (II) for each theoretically active amine hydrogen atomcontained in component (I).
 4. A composition of claim 3 wherein(a)component (I-A) is acrolein, crotonaldehyde or a combination thereof;(b) component (I-B) is ethylenediamine, diethylenetriamine,triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine,hexaethyleneheptamine or any combination thereof; and (c) component (II)is tall oil fatty acid.
 5. A composition of claim 1 wherein the reactionproduct of components (I-A) and (I-B) is an oligomer having an aminehydrogen equivalent weight of from about 50 to about
 80. 6. Acomposition of claim 2 wherein the reaction product of components (I-A)and (I-B) is an oligomer having an amine hydrogen equivalent weight offrom about 50 to about
 80. 7. A composition of claim 3 wherein thereaction product of components (I-A) and (I-B) is an oligomer having anamine hydrogen equivalent weight of from about 50 to about
 80. 8. Acomposition of claim 4 wherein the reaction product of components (I-A)and (I-B) is an oligomer having an amine hydrogen equivalent weight offrom about 50 to about 80.